A Study of Effects of Changing the Position of the Tool Axis against the Machined Surface

The article focuses on monitoring the machined surface after it has been machined with different milling strategies. Different milling strategies refer to milling whilst changing the tool axis relative to the surface after finishing the free form milling. The research focuses mainly on the geometric characteristics of the finished surface profile and residual stresses in the surface layer. The goal of the experimental work is to find an effective position of the tool axis, or an effective interval of the tool axis, in relation to the machined surface normal. Practical applications of the results are focused on finishing milling of complicated shape surfaces especially in the production of moulds and dies for the automotive and aerospace industries. The technology is based on the substitution of three-axis milling for multi-axis milling, i.e. mainly 5-axis simultaneous milling

Triaxial analysis of residual stress in surface layers after high feed machining using X-ray diffractometer

Continuously increasing of productivity is main cause of finding of new ways and methods of machining. High feed machining (HFM) is one of methods of high-productivity machining developed to achieve higher metal removal rates and decrease machining time. Each machining or treatment operation introduces residual stress into the material and its surface layers. Roughing methods of machining generate tensile residual stress obviously. Tensile character of residual stress is not suitable for functional properties of produced parts. In some cases, finishing methods of machining can improve residual stress to suitable character. New detection method of residual stress by applying of x-ray diffraction allows to measure residual stress as triaxial tensor and distribution of residual stress. When we know analyse the residual stress thoroughly, we can design right finishing method and so improve the character of residual stress. This article is focused on analysing given measuring method of residual stress in triaxial direction and next possibilities of their eventual improvement

Ceramic Cutting Tool Test with Interputted Cut Simulator

Ceramic cutting tools availability during interrupted machining was solution at this article, in the concrete ceramic DISAL D320 from Czech producer Saint Gobain Advanced Ceramic Turnov. Experiments were provided at special fixture – interrupted cut simulator. This fixture was constructed at Department of Machining and Assembly. Monitored parameter was number of shocks to totally destruction. The goals of tests were contribute to bigger using of these cutting materials at machining, especially at interrupted machining

Parameters Influence of CO2 Laser on Cutting Quality of Polymer Materials

The article deals with evaluating of the resulting surface state of the three plastic materials and identification of suitable conditions for laser cutting with CO2 tube. As representative were chosen polypropylene, polymethylmethacrylate and polyamide. When cutting these types of materials it could melt eventually their re-sintering. A suitable combination of parameters is possible to achieve of sufficient quality of the cut. The samples were cut at different feed speed and laser power. Then they was compared on the basis of the measured roughness parameters Ra a Rz by using a portable touch roughness Hommel-Etamic W5 and dates was processed according to ČSN EN ISO 4287. Cutting of samples was realized at the Department of Machining, Assembly and Engineering Metrology, VŠB-TUO

Triaxial analysis of residual stress in surface layers after high feed machining using X-ray diffractometer

Continuously increasing of productivity is main cause of finding of new ways and methods of machining. High feed machining (HFM) is one of methods of high-productivity machining developed to achieve higher metal removal rates and decrease machining time. Each machining or treatment operation introduces residual stress into the material and its surface layers. Roughing methods of machining generate tensile residual stress obviously. Tensile character of residual stress is not suitable for functional properties of produced parts. In some cases, finishing methods of machining can improve residual stress to suitable character. New detection method of residual stress by applying of x-ray diffraction allows to measure residual stress as triaxial tensor and distribution of residual stress. When we know analyse the residual stress thoroughly, we can design right finishing method and so improve the character of residual stress. This article is focused on analysing given measuring method of residual stress in triaxial direction and next possibilities of their eventual improvement

Triaxial analysis of residual stress in surface layers after high feed machining using X-ray diffractometer

Continuously increasing of productivity is main cause of finding of new ways and methods of machining. High feed machining (HFM) is one of methods of high-productivity machining developed to achieve higher metal removal rates and decrease machining time. Each machining or treatment operation introduces residual stress into the material and its surface layers. Roughing methods of machining generate tensile residual stress obviously. Tensile character of residual stress is not suitable for functional properties of produced parts. In some cases, finishing methods of machining can improve residual stress to suitable character. New detection method of residual stress by applying of x-ray diffraction allows to measure residual stress as triaxial tensor and distribution of residual stress. When we know analyse the residual stress thoroughly, we can design right finishing method and so improve the character of residual stress. This article is focused on analysing given measuring method of residual stress in triaxial direction and next possibilities of their eventual improvement

Influence of Coolant Pressure Size on Surface Roughness when Stainless Steel Machining

The paper is focused on the influence of the coolant pressure on the surface roughness of the workpiece when machining stainless steels. The components were machined on a STAR SR-32J dual spindle machining center and an external cooling unit HYTEK CHAV 160/150-AF-F-OL was used for cooling. Two stainless steel components were investigated, namely the gas control valve rod and the high-pressure control valve housing, which require low roughness Ra after machining (less than 0.375 and 0.25 micrometers respectively). The first component was tested at 8 different pressures in the range of 150 bar - 10 bar and the second component at 4 different pressures in the range of 120 bar - 10 bar. The roughness parameters were measured by the contact method using the MITUTOYO Surftest SJ-410 Roughness Tester and the Alicona InfiniteFocus optical microscope. Based on these sample input parameters, it was evaluated howmuch the pressure affects the surface quality or suggested its reduction due to the high cost of operation of the external high-pressure equipment